Ghosts and ghouls know no rules! Remember that maxim when seeking Halloween decorating ideas for your yard. Halloween is the holiday par excellence for creative decorating. And don't forget to incorporate unusual plants in your macabre landscape! Specimens that lend themselves to that creepy, "Addams Family" feel include black plants, weeping trees and contorted shrubs (see photo at right of a contorted hazelnut, courtesy of the Missouri Botanical Garden). In addition, learn how to make a better jack-o'-lantern by making the switch from pumpkins to hardshell gourds.